The invention relates to a carbonaceous adsorbent which is composed of finely divided carbonaceous materials and binders and is made by a low temperature treatment of the bodies formed of such material and if desired activation at temperatures between 600.degree. and 1000.degree. C. by means of hydrogen and/or carbon dioxide.
When making carbonaceous adsorbents it is desirable to adjust the adsorption properties and the pore system of the adsorbents according to the contemplated use. Because of the many different problems which for instance arise in the purification of flue gases and sewage waters one tries to be in possession of as broad a spectrum of differentially effective absorbents as possible.
It is known to make pressure and abrasion resistant activated carbons from finely divided carbonaceous materials by shaping, low temperature heating and activation using as binder plastic systems consisting of a mixture of phenols and aldehydes and/or their condensation products (German published application 23 22 706). This application also discloses that pulverulent activated carbons can be formed with solutions of polymers followed by drying and a pyrolysis step in which the binding agent forms a cokelike residue.
It has also become known that activated carbons can be made exclusively from organic polymers by thermic comminution of synthetic plastics either in individual form or in mixture of several plastics (thesis by R. F. Muller, Institute of Technology, Zurich 1972"Uber die Herstellung von Aktivkohlen aus organischen Kunststoffen und die Charakterisierung poroser Stoffe"). Neither in these instances nor in other prior art processes for making activated carbons with pitch as binding agents has it been accomplished that the pore systems can be adjusted across the entire range of pore radii.
It is therefore an object of the invention to provide an adsorbent with adjustable adsorption properties and pore types which can be used for entirely different uses.